FULL PROJECT 2: DETERMINING OPTIMAL ANAL CANCER PREVENTION STRATEGIES FOR HIV-INFECTED INDIVIDUALS LIVING IN PUERTO RICO PROJECT SUMMARY/ABSTRACT Squamous cell carcinoma of the anus (SCCA) is an epidemic among persons living with HIV (PLWH). Studies in the US and Puerto Rico (PR) have reported >80-fold risk of SCCA among PLWH when compared with the general population. Guidelines based on expert opinion recommend anal cancer screening for PLWH. To inform evidence-based use of screening, studies are currently underway; however, findings from those studies will not be generalizable to PLWH in PR. This is because racial and ethnic composition, disease prevalence, anal cancer treatment outcomes including cost and quality of life (QOL) substantially differ for PLWH in PR. This increases the importance of anal cancer screening evaluation specifically and separately for PLWH in PR majority of which are of Hispanic origin. Furthermore, no ongoing or future randomized controlled trials (RCTs) will evaluate mortality benefits of screening as it unethical to evaluate a ?no screening? arm. As such, a mathematical model (incorporating epidemiological, cost, and quality of life data specific to PLWH in PR) could be utilized as a unique tool to evaluate survival and QOL benefits and cost-effectiveness of screening with the goal to promote health and value-based care. Our overarching goal is to optimize anal cancer prevention for PLWH in PR. We will study the epidemiology of SCCA, and evaluate the cost of and QOL after SCCA treatment to inform a mathematical model that will determine the best screening regimen for PLWH in PR. We also seek to study critical barriers and facilitators necessary to decrease potential uncertainty in screening adoption and adherence to screening recommendations. Our Specific Aims are: (1) Determine epidemiological, cost, and QOL measures of anal precancer and cancer among PLWH living in PR. (2) Identify barriers to and facilitators of screening for anal cancer, and adherence to anal cancer screening and high-grade squamous intraepithelial lesions (HSIL) treatment. (3) Construct and execute a mathematical model to determine effective and cost-effective screening strategies for the detection of anal precancer among PLWH in PR. (4) Use value of information (VOI) analysis to determine high priority future clinical studies to improve screening accuracy and adherence to screening recommendations. In Aims 1 and 2, we will perform secondary data analyses of existing databases, and conduct focus groups and three epidemiologic studies (two cross-sectional studies and one cohort study) that involve patient recruitment. Parameters identified through these activities will inform the development of the SCCA screening model and the execution of the VOI analysis (Aims 3 and 4). The end result of this study will be utilized to inform an optimal anal cancer screening regimen specific to PLWH in PR.